mcalpine



UNITED STATES PATENT OFFICE.

cRAs. RoNTEz AND o. L. MOALPTNE, oEjNEw YORK, N. Y.

@IMPROVEMENT IN FORMING SUB-FOUNDATIONS.

Specification forming part of VLetters Patent No. 36,9173, datedNovember 11, 1862 antedated May 11, 1862.

'To a/ZZ whom it may concern:

by any of the known methods to any desired v depth, have directly beenfilled with sand or concrete. This is done, mainly, with the intentionto impart solidity and inertia to the hollow bodies.

In operating with our improvement we do :not proceed to lill the hollowpile; but we form a foundation of concrete or other solid ma terial,which extends laterally beyond and beneath the area inclosed by thehollow pile. Thus a permanent sub-foundation is formed having a largerbearing-surface than the original foundation hollow pile.

'Io enable others to use our invention, we will proceed to describe ourmode of working.

When, for example, an iron cylinder six feet in diameter has been sunkthrough water, sand, clay, or other material to any desired depth, themen inside the cylinder, working in a condensed atmosphere, excavateunder its lower edge laterally and downward for several feet, thedistance and depth depending on the character of the soil and theauxiliary means used to prevent it from caving in. The space excavatedis filled with concrete or other suitable solid material. In this mannersuc cessive portions are excavated until an enlarged area is formed,which sustains the cylinder. The process may further be continued bydrawing up the cylinder some distance, and in like manner layingsuccessive courses of concrete masonry or other solid mate-- In theaccompanying drawings, lFigure 1 is a longitudinal elevation showing acylinder sunk through water, sand, clay, or other maA terial and restingon a concrete sub-foundation. Fig. 2 is atransverse section of thecylinder at its base, with the concrete founda` tion laid in sections.

Letter A is the cylinder, and .B the concrete foundation.

We do not claim the sinking hollow piles through sand, clay, or othermaterial, nor the filling in of the. same with concrete or other solidmaterial; but

What we claim, and desire to secure by Letters Patent, is

The method of forming sub-foundations, as

herein shown and described, which consists substantially in extendingthe foundation from within the tube, as set forth.

CHARLES PONTEZ. C. L. MGALPINE.

Witnesses:

N. LocKwooD, FRED. A. HAcKLEY.

